Low elevation angle propagation measurements in the 6/4 GHz and 14/11 GHz bands

Attention is given to the results of a series of low elevation angle propagation experiments conducted around the world in the 6/4 GHz and 14/11 GHz bands, as part of the Intelsat propagation measurements program. The theoretically predicted increases in attenuation, depolarization, and tropospheric scintillation magnitudes with decreasing elevation angle are verified by the results obtained; it is in addition noted that temperature and humidity can be well correlated with tropospheric scintillation, and that while the incidence of ice depolarization increases as path elevation is reduced, this effect is not systems-limiting. Rain attenuation and rain depolarization are the major propagation impairments.